1. Field of the Invention
The present invention relates to a vacuum cleaner, and particularly, to a dust collection unit for a vacuum cleaner, which can automatically remove foreign objects clogging the filter unit. More particularly, the present invention relates to a dust collection unit for a vacuum cleaner, which can efficiently remove foreign objects adhered to a surface of a porous filter unit while air passes through the dust collection unit and reduce noise generated during the cleaning of the porous filter unit.
2. Description of the Related Art
A vacuum cleanser is classified into a canister type and an upright type. The former includes a suction nozzle unit sucking air containing foreign object while moving along a floor, a main body with a unit for generating air suctioning force through the suction nozzle unit, a dust collection unit for filtering foreign object contained in the air sucked into the main body, and an operating unit mounted on the main body so that a user grasps the operating unit in use. The suction nozzle unit, the main body, the dust collection unit, and the operating unit are integrated in a single body. The latter includes a suction nozzle unit and a main body receiving a dust collection unit. The suction nozzle unit and the main body are provided in separated units. A flexible hose is provided to interconnect the suction unit and the main body. Therefore, the cleaning is performed while moving the suction nozzle unit in a state where the main body is fixed at a location.
That is, the dust collection unit includes a cylindrical dust collection container and upper and lower covers that defines a top and bottom of the dust collection container, respectively. A suction guide is formed on a portion of the dust collection container to suck outer air and an outlet guide is provided on another portion of the dust collection container to exhaust the air from which foreign objects are removed.
In addition, a filtering unit is provided on an inner surface of the dust collection container to filter off dirt particles among the foreign objects sucked into the dust collection container. The filter unit is classified into a cyclone type separating foreign objects having heavy self-weight in cyclone airflow and a porous filter type for filtering off foreign objects greater than a predetermined volume while air containing the foreign objects passes through a porous filter. In order to improve the foreign object removal efficiency, both of these two types of filter units are generally provided in the dust collection unit. That is, the porous type filter unit is installed in the cyclone type filter unit. Therefore, the relatively large-sized foreign objects are first filtered off by the cyclone type filter unit and the relatively small-sized foreign objects are secondary filtered off by the porous type filter unit.
The constitution and operation of the filter unit will be described in more detail hereinafter.
The cyclone type filter unit is provided in the dust collection container and the porous type filter unit is installed in the cyclone type filter unit. When the air is introduced into the dust collection unit, the air flows in cyclone pattern in the cyclone type filter unit. At this point, the foreign objects heavier than the air fall down to be stored a separated foreign object-storing chamber. The foreign objects that are not removed by the cyclone type filter unit are filtered off by the porous filter unit while the air passes through the porous filter unit.
At this point, dirt particles may clog the surface of the porous filter unit. When the amount of the dirt particles clogging the surface of the porous filter unit is increased, airflow resistance is increased to deteriorate the air suctioning force. Furthermore, the motor may be overloaded. When the dirt particles are tightly adhered to the surface of the porous filter unit, it is difficult to remove the same from the porous filter even when the cleaning operation is performed.